1. Field of the Invention
The present invention relates to a flying magnetic head device mounted on a magneto-optical disk apparatus or the like and, more particularly, to a magnetic head device which provides improved shock resistance.
2. Description of the Related Art
FIG. 5 is a partial perspective view illustrating a conventional magnetic head device employed for a magneto-optical disk apparatus.
The magnetic head device is composed of a head main body 25, a flexure 50, and a support member 40.
The head main body 25 has a slider 26 opposed to a record medium, a core assembly 27 being retained by the slider 26; in FIG. 5, the bottom surface is the surface opposed to the record medium, while the upper surface is the surface supported by the support member 40.
The core assembly 27 is composed primarily of a core and a coil 30 wound around the core, a magnetic gap (not shown) of the core assembly 27 appears at the bottom surface of the slider 26.
The flexure 50 is formed using a thin flat spring; it is provided with a fixed portion 51 and a tongue portion 52.
The fixed portion 51 has a positioning hole 54. Projecting portions 55 and 55 are formed on both sides of the fixed portion 51; the projecting portions 55 and 55 are inserted in grooves 28 and 28 of the slider 26, and the tongue portion 52 of the flexure 50 and the slider 26 are secured by bonding or other similar means.
The top surface of the tongue portion 52 of the flexure 50 is held against a pivot 46 (butting portion) formed on an adapter 43 which will be discussed later, and the slider 26 is free to change the position thereof, using the apex of the pivot 46 as the supporting point thereof.
The support member 40 is constituted by a load beam 41 and the adapter 43. The load beam 41 is made of a flat spring material; it has bent portions 41a and 41a which are formed on both edges thereof and which extend from the middle toward the distal end thereof; these portions are rigid, and a predetermined elastic pressing force at the proximal end of the load beam 41. The load beam 41 further has a pair of positioning holes 42 and 42.
The adapter 43 has a concave shape; it has positioning holes 44a and 45a formed in lugs 44 and 45 thereof. With the positioning holes 44a and 45a aligned to the positioning holes 42 and 42 of the load beam 41, the adapter 43 is welded to the load beam 41. The adapter 43 has a stepped section on the bottom surface thereof; the pivot 46 is formed on the higher bottom surface, the pivot jutting out downward spherically. Formed in the lower bottom surface of the adapter 43 is a positioning hole 48; with the positioning hole 48 aligned with the positioning hole 54 of the flexure 50, the fixed portion 51 of the flexure 50 and the adapter 43 are secured in a predetermined area A by welding, bonding, or the like.
In general, the magneto-optical disk is housed in a cartridge to protect the surface of the disk. When the cartridge is placed in the apparatus, the shutter provided on the cartridge is released to open the window portion of the cartridge, so that the head main body 25 shown in FIG. 5 moves into the cartridge through the window portion and the head main body 25 comes in contact with the top surface of the disk. As the disk in the cartridge turns, the airflow on the top surface of the disk causes the head main body 25 to float and the magnetic gap appearing at the bottom surface of the slider 26 in turn causes a perpendicular magnetic field to be applied to the disk. A laser beam is radiated from the opposite side of the disk to record information by light modulation or magnetic field modulation.
In recent years, the head main body 25 has been made smaller, and this has called for the need to reduce the rigidity of the flexure 50. If the flexure 50 retains high rigidity while the head main body 25 has been made smaller, then it would be difficult for the head main body 25 to freely rock, using the pivot 46 formed on the adapter 43 as the supporting point. This leads to a problem, for example, in that the head main body 25 can no longer accurately follow the vertical movement of the record medium or pits and projections on the top surface of the record medium.
To reduce the rigidity of the flexure 50, it is necessary to reduce the thickness of the flexure 50. Reducing the rigidity of the flexure 50, however, poses the following problem. As shown in FIG. 5, the top surface of the flexure 50 is fixed to the adapter 43 by the predetermined area A, while the other end is a free end. Hence, if the rigidity of the flexure 50 is reduced, then the free end of the flexure 50 may be shaken and elastically deformed if the magnetic head device is subjected to a strong impact during the assembly process or the like or if the head main body 25 is subjected to an external force. Further, with the magnetic head device installed on a magneto-optical disk apparatus, if an impact is applied to the entire apparatus, then the head main body 25 may shake severely and may hit the magneto-optical disk, damaging the disk, or the head main body 25 may hit other adjacent components and damage the head main body 25 when the head main body 25 withdraws.